Co-Catalyzed Cyclooctatriene Synthesis by [4+2+2] Cycloaddition

Significance

This atom-economical reaction catalyzed by a Co-diimine complex provides access to a number of functionalized cyclooctatrienes in good yields. Internal alkynes give the highly substituted products in somewhat lower yields. It has been found that the use of Fe powder increases the yield of cyclooctatriene.